Mixtures of ethyl cellulose (Sigma Aldrich, St. Louis, MO)-ethanol (200 proof, Koptec, King of Prussia, PA) and ethanol were prepared by stirring at room temperature. Ethyl cellulose concentration ranged from 0–6% (ethyl cellulose to ethanol, weight:weight). Concentrations greater than 6% ethyl cellulose were not evaluated because they did not fully dissolve in ethanol at room temperature. Solution viscosity was measured with a Brookfield Model RV-DVIII Ultra Programmable Rheometer (Brookfield Engineering, Middleboro, MA) at room temperature. The cone number was a CP-40. The range of shear rates tested spanned two decades to simulate the range of shear rates during injection. Data were only accepted for torques between 10 and 100% (this falls within the published sensitivity of the rheometer). To obtain a viscosity value, three viscosity measurements at each shear rate were averaged. Given that rheological behavior was Newtonian (viscosity was independent of applied shear rate), values across all shear rates were then averaged to characterize each ethyl cellulose concentration.

Ethyl cellulose is currently approved by the US FDA as a food additive and costs less than $0.50/gram.

And the application method:

Figure 1 illustrates the design of these experiments. For evaluation of varying injection rate and ethyl cellulose concentration, the average tumor volume was 195 ± 140 µL (mean ± s.d.). 50 µL of solution (either pure ethanol or 3% ethyl cellulose-ethanol) was injected into the center of the tumor. Injection volume was always less than tumor volume (about 25% of tumor volume, as compared to 400% in the control studies with pure ethanol that simulated current clinical practice). Injection rates were 0.1, 1.0 or 10 mL/hr (achieved using the syringe pump) or ~100 mL/hr (achieved manually). Notably, the rate of 10 mL/hr has been suggested as optimal for gene delivery into tumors27. Tumor volume was measured before injections, and at 1, 2, 4, and 7 days thereafter. For tumors that did not respond completely and were still present and growing after day 7, repeat ablations were performed (as for controls, above). These were treated as independent ablations (i.e., as though they were new tumors, as described above; justification for treating repeat injections as independent is shown in Supplementary Figure 1). Repeats were only performed if the tumor volume had increased for two consecutive days after the 7-day observation period. 36 total ablations were performed on 8 animals. 15 injections were repeat injections, and multiple tumors from each hamster were treated.

D, you know we should probably look for a resource that has the different cancer medicines used in different developing nations. From what I read, ethanol is a widely used treatment in these nations. The ethyl cellulose by keeping the ethanol inside the tumor longer was the innovation. I had not been aware of ethanol as a cancer treatment before.